The USB specification calls for very tight control of the electrical signaling on the USB cable. USB is generally described at www.usb.org. Specialized testing fixtures and methods used for validating USB signal integrity (USB IF test) is generally described at http://www.usb.org/developers/compliance/. The USB IF test involves a lengthy and expensive data collection system.
Therefore, there is a need for a simpler and lower cost test that may be completed for preliminary validation of USB operation to help assure first pass design success of the more complex and costly USB IF test.